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<p>For the past two decades, the measurement of nitrous oxide (<span class="inline-formula">N₂O</span>) isotopocules – isotopically substituted molecules <span class="inline-formula">¹⁴N¹⁵N¹⁶O</span>, <span class="inline-formula">¹⁵N¹⁴N¹⁶O</span> and <span class="inline-formula">¹⁴N¹⁴N¹⁸O</span> of the main isotopic species <span class="inline-formula">¹⁴N¹⁴N¹⁶O</span> – has been a promising technique for understanding <span class="inline-formula">N₂O</span> production and consumption pathways. The coupling of non-cryogenic and tuneable light sources with different detection schemes, such as direct absorption quantum cascade laser absorption spectroscopy (QCLAS), cavity ring-down spectroscopy (CRDS) and off-axis integrated cavity output spectroscopy (OA-ICOS), has enabled the production of commercially available and field-deployable <span class="inline-formula">N₂O</span> isotopic analyzers. In contrast to traditional isotope-ratio mass spectrometry (IRMS), these instruments are inherently selective for position-specific <span class="inline-formula">¹⁵N</span> substitution and provide real-time data, with minimal or no sample pretreatment, which is highly attractive for process studies.</p> <p>Here, we compared the performance of <span class="inline-formula">N₂O</span> isotope laser spectrometers with the three most common detection schemes: OA-ICOS (<span class="inline-formula">N₂</span>OIA-30e-EP, ABB – Los Gatos Research Inc.), CRDS (G5131-i, Picarro Inc.) and QCLAS (dual QCLAS and preconcentration, trace gas extractor (TREX)-mini QCLAS, Aerodyne Research Inc.). For each instrument, the precision, drift and repeatability of <span class="inline-formula">N₂O</span> mole fraction <span class="inline-formula">[N₂O]</span> and isotope data were tested. The analyzers were then characterized for their dependence on <span class="inline-formula">[N₂O]</span>, gas matrix composition (<span class="inline-formula">O₂</span>, <span class="inline-formula">Ar</span>) and spectral interferences caused by <span class="inline-formula">H₂O</span>, <span class="inline-formula">CO₂</span>, <span class="inline-formula">CH₄</span> and <span class="inline-formula">CO</span> to develop analyzer-specific correction functions. Subsequently, a simulated two-end-member mixing experiment was used to compare the accuracy and repeatability of corrected and calibrated isotope measurements that could be acquired using the different laser spectrometers.</p> <p>Our results show that <span class="inline-formula">N₂O</span> isotope laser spectrometer performance is governed by an interplay between instrumental precision, drift, matrix effects and spectral interferences. To retrieve compatible and accurate results, it is necessary to include appropriate reference materials following the identical treatment (IT) principle during every measurement. Remaining differences between sample and reference gas compositions have to be corrected by applying analyzer-specific correction algorithms. These matrix and trace gas correction equations vary considerably according to <span class="inline-formula">N₂O</span> mole fraction, complicating the procedure further. Thus, researchers should strive to minimize differences in composition between sample and reference gases. In closing, we provide a calibration workflow to guide researchers in the operation of <span class="inline-formula">N₂O</span> isotope laser spectrometers in order to acquire accurate <span class="inline-formula">N₂O</span> isotope analyses. We anticipate that this workflow will assist in applications where matrix and trace gas compositions vary considerably (e.g., laboratory incubations, <span class="inline-formula">N₂O</span> liberated from wastewater or groundwater), as well as extend to<span id="page2798"/> future analyzer models and instruments focusing on isotopic species of other molecules.</p>